PROCEEDINGS lix 



result attained after careful and persistent investigation ; and the fortunate 

 individual who succeeds in penetrating her laboratory and secures the formula 

 for heatless light will win fortune and undying fame. 



Another line of investigation which looks inviting is that of phosphorescence 

 and storage of light waves as exhibited by calcium sulphide or luminous paints ; 

 and it is within the range of probability to suppose that a luminous compound 

 will be discovered that will store up the rays of the sun and return them to us 

 when needed at night, not in the feeble glow of the luminous match safe, but 

 with a brilliancy sufficient for all purposes of illumination. 



Those who have witnessed Tesla's experiments at the World's Fair will remem- 

 ber the particularly brilliant effect produced when the talented experimenter 

 held in his hand a large glass tube containing but a trace of air and which, though 

 totally disconnected from any visible circuit, glowed with a soft pulsating light 

 of considerable intensity but practically heatless, and we have been told that in 

 the near future we shall light our houses by placing metalic plates on the walls 

 of our rooms and connecting them with a source of a high potential and fre- 

 quency, and our lamp being simply an exhausted bulb or globe will glow in anjy 

 part of the room and will need no connection, the light being produced by the 

 rapidly changing electrostatic stress between the walls of the room or plates. 



Unfortunately, however, in this method wliich uses such extremely high poten- 

 tials and frequencies the ordinary methods of transmission or wiring fail and the 

 effect more nearly approaches the rapidly alternating discharge of lightning in 

 that a metalic circuit is practically opaque, so to speak, to a current of say 

 1,000,000 volts and the same number of alternations. The self-induction of such 

 a circuit with currents of moderate potential and frequency would be practically 

 nothing, but is something enormous with the above pressure and frequency, and 

 so far as M'e can see this system if it attains to any degree of perfection will have 

 a very limited lield from this effect alone, to say nothing of the severe dielectric 

 stresses. 



Whether electricity will play an important part in the light of the future or 

 not is a matter of speculation, and it would not be strange if the coming system 

 were largely a chemical one, though electricity will no doubt be the form of 

 energy used to the points of conversion. However, in any case our present elec- 

 tric light plants will not go out of existance, but will fully occupy the field they 

 are only now entering, for the distribution of power and heat for all purposes. 



In conclusion, it may be said that no field is so rich and none so pregnant with 

 good possibilities, but the problem must be worked out on new lines, bearing in 

 mind that any light that depends on carbon as the source of illumination will 

 inevitably consume 90 per cent, of the energy put into the process, in the form 

 of heat, and it matters not whether this energy is supplied by burning gas or the 

 electric current, the results are practically the same, and no great improvement 

 can be obtained till we find out how to separate heat and light, or produce either 

 form of radiation at will." 



